Over on the 'Mart, Anacortes has announced a limited production SV 4" achromat dubbed the "Planet Killer". Supposedly only 24 scopes. Price is $799, IMHO a little high, but I don't know, maybe something special about it,at F/11 though, I don't see how. For a planet killer wouldn't you want an f/15 like the Antares offering?

Isn't a planet KILLER what Marvin the Martian was always trying to build in the cartoons?

I prefer the term "planet viewer";and I agree that F15 certainly would be more desirable unless the scope were made with ED glass.Matter of fact ,putting awkwardness of the physical tube aside, it would be even better were the 4" an F20.The old 80mm/1600m were said to be excellent in terms of sharopness and lack of false color.

I guess it is marketing and shipping constraints that bias manufacturers against long tubes.

You can get the original version of this scope that Stellarvue sold very briefly from Canadian Telescopes for $500 with free shipping, it differs from the new premium version by having a 2" crayford instead of a 2.5" R&P and it doesn,t have a removable section for bino viewing however its $300 cheaper, it was reviewed in S&T and did very well though that sample came from Hands On Optics.DA.

My bet is that it isn't a clone at all, but rather the exact same scope from the same Chinese supplier. A quick switcheroo of the focusers and what do you have? A brand new Stellarvue one-of-a-kind product!

I don't know Jon...I kill planets most every evening with my 4" APO. They seem to be rather easy to target and kill in multiple ways with a 4" optic Even when the 10" is out with it the 4" still bags its prey and kills those planets very reliably and enjoyingly In my book, any scope can properly designate itself as a planetary killer as long as it deviates from the common popular design in order to maximize its potential for planetary observing. For an achromat, this would of course be making it in a bit longer than the common focal ratio. FWIW, I don't find aperture much of an issue for planet killing...even my "challenge" planet killer 60mm (f/16.7) performs some increadible feats of planetary detail.

I see no need to deviate from the common, popular design for a telescope to be a "planet killer", it just needs to be a scope that is capable being seeing limited nearly all the time.

That would not work for me because that is an aperture-only approach. Plus I wonder how valid it really is? Most people will say in a heartbeat that for the typical observer in the typical circumstance that it is hightly unlikely that the seeing will be producing sub 1 arcsec of resolution...and many professional observatories strive to find places that can routinely provide this. So if that is the premise for the typical better evening, then seeing-limited becomes a 115mm scope for a 1 arcsecond atmosphere (probably why the 130mm class refractor is so popular)!! Then there is the issue of while larger scopes may be better seeing-limited for rarer evenings, they typically are not thermal-ready in any amount of real-time without considered prep and supplemental active cooling. So for these, a "planet-killer" designation for me would mean it needs to deviate quite a bit from the norm. e.g., if a Dob it needs longer throw for smaller CO and a tracking table and lots of active cooling mods and an easily accessible mirror for dust cover and frequent cleaning ease and probably not a truss design as these are more sensitive to going out of collimation depending on their orientation depending on the truss pole arrangement.

Yes, it may be a great scope for 4", but for peopie that want better planetary views, there are so many far better choices than a small achromat.

Marketing is marketing though, and if people believe that they can somehow see more because it is a "Planetary scope," then the marketing people have earned their money buy getting the buyer to go for a 4" scope rather than something more capable.

I have owned an aweful lot of telescopes, and the vast majority of them have been better planetary scopes than any 4" telescope I have ever owned.

From my point of view, a "planet killer" is a scope capable of providing the best possible planetary views under almost all circumstances.

I don't consider my 4 inch apo or any 4 inch scope to be a "planet killer" because most nights there is more to see than can be seen with any 4 inch scope.

Jon Isaacs

Not where I (and I'm sure many others) live. On most nights for a lot folks, seeing is going to be the limiting factor in planetary viewing. A good four inch refractor is more than capable of "killing" some planets.

That would not work for me because that is an aperture-only approach. Plus I wonder how valid it really is? Most people will say in a heartbeat that for the typical observer in the typical circumstance that it is hightly unlikely that the seeing will be producing sub 1 arcsec of resolution...and many professional observatories strive to find places that can routinely provide this. So if that is the premise for the typical better evening, then seeing-limited becomes a 115mm scope for a 1 arcsecond atmosphere (probably why the 130mm class refractor is so popular)!!

It doesn't take 1 arc-second seeing for an 8 inch telescope to perform better than a 4 inch. Planetary observing is different than resolving double stars but "over sampling" is useful in either. To split a 1.15 arc-second double star (Dawes limit) in a 4 inch scope, requires better than 1.15 arc-second seeing.

A couple of years back, there was a discussion about seeing versus Aperture in which Vladimar Sacek shared some results of simulations he had done.

"
That is probably as good a summary as one can come up with. If you look at those patterns, you'll see that if seeing improves to its average level (about 2 arcsec), the 16 inch will outresolve 4-inch, but will still be outresolved by 6-8 inch. If the seeing now swings to the opposite side, and improves to 1 arc second, the 16-inch outresolves the smaller apertures."

You can get the original version of this scope that Stellarvue sold very briefly from Canadian Telescopes for $500 with free shipping, it differs from the new premium version by having a 2" crayford instead of a 2.5" R&P and it doesn,t have a removable section for bino viewing however its $300 cheaper, it was reviewed in S&T and did very well though that sample came from Hands On Optics.DA.

I believe this assessment is correct. Stellarview initially sold the Kunming United 4" achromat before deciding to limit their scopes to ED/Apos. Their early version was identical to the Canadian Telescopes and Astrotelescopes (Hands On Optics) versions except apparently a shortened dew shield. Subsequently, the Astrotelescopes version gained an upgraded rack and pinion focuser apparently of Long-Perng manufacture. This is the version I bought late last year.

Interestingly, my Astrotelescopes version arrived from HOO in packaging showing it originated at Stellarview.

I'm a bit surprised that Stellarview has introduced another non-apo.

Btw: Hands On Optics has also called their version a "planet killer" too. I'll avoid the debate but will say the optical performance of my scope is superb.

Likewise, as I don't use a binoviewer it's hard for me to assess whether $200 extra for the removable section of tube is a good value for someone that does use both eyes.

All in all though, I am extremely satisfied with the optical performance and mechanical build of my AT102F11.
Just my 2 centavos.

I guess it is marketing and shipping constraints that bias manufacturers against long tubes.

I'm guessing it is also user friendliness that factors into the marketing decisions that affect what telescope design gets priority as to hitting the production lines. An F/15 or worse,an F/20 tube is extremely long and requires a really substantial mount that for a user such as myself wouldn't even entertain to owning due to my situation of not being able to permanently mount that setup in some sort of observatory. I have to take each and every telescope setup I own outdoors everytime it gets used,then reverse the proceedure when it's time to call it a night. That's my bias against this design because it requires far less effort to choose a completely different one like a 10 inch dobsonian that is far easier for me to get into action, with more horsepower under the hood in terms of resolution capability. My opinion is there many other backyard observers in the same boat,and that isn't lost on the scope manufacturers. I love 4 inch refractors that are a lot more grab and go capable and believe that desire is more widespread in this hobby.

In the right circumstances for the right individual, a long tubed acro can be a wonderful tool.

Having an Orion 100ED which is optically excellent and multiple Catadioptric scopes, my assessment of what a planetary scope differs. While the 100ED delivers great images it never delivered better views than the Intes 6.5" scope even in average seeing. The newly acquired 8"SCT further outpaces the 100ED and the Intes. I believe 6-8" of apertures are necessary for a true planetary scope.

Is this new SV scope really any different than the Astro Telescope from HOO?

Here is a quote from Vic's post on the Yahoo Stellarvue Group:

"So this month, for at least a limited time, I will produce another Stellarvue achromatic refractor, with performance on the level people expect from us. These will not be mere import telescopes which are untested and inconsistent. These telescopes will be triple tested by us, just like any other Stellarvue telescope. Only the best optics can survive our testing regiment.

Now this will be a visually oriented telescope with a long enough focal length to ensure excellent planetary performance. It will come with our highly praised 2.5" dual speed rack and pinion focuser, giving over-the-top mechanical performance. But let's not stop here. We will incorporate a 4 3/4" removable extension in front of the focuser. Remove this extension and you can use bino viewers without any correction lenses (OCA's or OCS's) which means you get a brighter image and a wider field of view when using bino viewers..."

Now, this scope is an achromat, (and also an aplanat.) Vic said he will disclose glass types later, but quickly admits that this is not using apo or ED glass.

"So this month, for at least a limited time, I will produce another Stellarvue achromatic refractor, with performance on the level people expect from us. These will not be mere import telescopes which are untested and inconsistent. These telescopes will be triple tested by us, just like any other Stellarvue telescope. Only the best optics can survive our testing regiment."

I guess it is marketing and shipping constraints that bias manufacturers against long tubes.

I'm guessing it is also user friendliness that factors into the marketing decisions that affect what telescope design gets priority as to hitting the production lines. An F/15 or worse,an F/20 tube is extremely long and requires a really substantial mount that for a user such as myself wouldn't even entertain to owning due to my situation of not being able to permanently mount that setup in some sort of observatory. I have to take each and every telescope setup I own outdoors everytime it gets used,then reverse the proceedure when it's time to call it a night. That's my bias against this design because it requires far less effort to choose a completely different one like a 10 inch dobsonian that is far easier for me to get into action, with more horsepower under the hood in terms of resolution capability. My opinion is there many other backyard observers in the same boat,and that isn't lost on the scope manufacturers. I love 4 inch refractors that are a lot more grab and go capable and believe that desire is more widespread in this hobby.

In the right circumstances for the right individual, a long tubed acro can be a wonderful tool.